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United States Patent |
6,102,934
|
Li
|
August 15, 2000
|
Anchor tool and method and apparatus for emplacing anchor in a borehole
Abstract
A method for emplacing a medical anchor in a borehole in biological tissue,
the method comprising the steps of providing a borehole in the biological
tissue, inserting the anchor into the borehole with a tool such that the
anchor is affixed to the tool and in approximate alignment with the
borehole, manipulating the tool, the step of manipulating the tool causing
the anchor to pivot about an axis perpendicular to the borehole and
further comprising rotating the anchor in the borehole about the axis of
the borehole, thereby causing the anchor to move outwardly in the borehole
to engage a wall of the borehole and cut into the wall of the borehole and
secure the anchor in a final position in the borehole such that the anchor
is disposed approximately perpendicular to the axis of the borehole; and
removing the tool from the borehole by moving the tool proximally in the
borehole, thereby separating the anchor from the tool and leaving the
anchor secured in the borehole.
Inventors:
|
Li; Lehmann K. (716 E. Broadway, Milford, CT 06460)
|
Appl. No.:
|
088572 |
Filed:
|
June 2, 1998 |
Current U.S. Class: |
606/232 |
Intern'l Class: |
A61B 017/04 |
Field of Search: |
606/232,72-73,228,74-75
|
References Cited
U.S. Patent Documents
2213715 | Sep., 1940 | Monohan.
| |
4741330 | May., 1988 | Hayhurst.
| |
4759765 | Jul., 1988 | Van Kampen.
| |
4776330 | Oct., 1988 | Chapman et al.
| |
4823794 | Apr., 1989 | Pierce | 606/232.
|
4898156 | Feb., 1990 | Gatturna et al.
| |
5002574 | Mar., 1991 | May et al.
| |
5163946 | Nov., 1992 | Li.
| |
5203787 | Apr., 1993 | Noblitt et al.
| |
5217486 | Jun., 1993 | Rice et al.
| |
5354298 | Oct., 1994 | Lee et al.
| |
5372604 | Dec., 1994 | Trott.
| |
5443482 | Aug., 1995 | Stone et al.
| |
5464425 | Nov., 1995 | Skiba.
| |
5464427 | Nov., 1995 | Curtis et al.
| |
5486197 | Jan., 1996 | Le et al.
| |
5531792 | Jul., 1996 | Huene.
| |
5540718 | Jul., 1996 | Bartlett.
| |
5545180 | Aug., 1996 | Le et al.
| |
5569303 | Oct., 1996 | Johnson.
| |
5941882 | Aug., 1999 | Jammet et al. | 606/73.
|
Foreign Patent Documents |
0270704 | Jun., 1988 | EP.
| |
2622430 | May., 1989 | FR.
| |
Primary Examiner: Buiz; Michael
Assistant Examiner: Trinh; Vikki Hoa B.
Attorney, Agent or Firm: Ostrolenk, Faber, Gerb & Soffen, LLP
Claims
What is claimed is:
1. A medical anchor for emplacement in a borehole in biological tissue, the
anchor comprising:
a central portion;
at least one outer portion attached to the central portion, the outer
portion having a cutting edge;
the anchor being adapted to be inserted in the borehole in approximate
alignment with a longitudinal axis of the borehole, and further being
adapted to be rotated in two axes to secure the anchor in the borehole, a
first axis of rotation being aligned with the axis of the borehole and a
second axis of rotation being perpendicular to the axis of the borehole,
further comprising a cam surface on said anchor for engagement by a
pushing member for causing said anchor to rotate about the second axis,
whereby the anchor moves outwardly about the second axis so that the
cutting edge cuts into a wall of the borehole and the anchor is rotated
about the first axis to achieve a final position substantially
perpendicular to the borehole.
2. The anchor of claim 1, wherein the anchor has two opposed outer
portions, each having a cutting edge on at least one side thereof, the
side of each portion having the cutting edge being opposite the side of
the other portion having the cutting edge.
3. The anchor of claim 1, wherein the anchor comprises a suture anchor and
further comprising at least one securement device for a suture in the
central portion.
4. The anchor of claim 3, wherein the securement device comprises at least
one aperture in the central portion into which a suture can be threaded.
5. The anchor of claim 4, wherein two apertures are provided in the central
portion through which a suture can be threaded.
6. The anchor of claim 1, wherein each outer portion has a sloped surface
terminating in a side comprising said cutting edge.
7. The anchor of claim 1, wherein the anchor has an attachment point for at
least of a material and device to be attached thereto, including a
prosthesis.
8. Apparatus for repairing a ligament or installing a ligament replacement,
the apparatus comprising:
a first anchor for attaching to a first end of one of the ligament and
ligament replacement;
a second anchor for attaching to a second end of one of the ligament and
ligament replacement;
the first and second anchors being attachable to the respective first and
second ends by suture;
the first and second anchors with the ligament or ligament replacement
being insertable through a first borehole disposed in a first bone member
into an aligned borehole in a second bone member such that the first
anchor is disposed in the aligned borehole and the second anchor is
disposed in the first borehole, the first anchor being rotatable about two
axes in the aligned borehole, one axis being perpendicular to the aligned
borehole and the other axis being aligned with the aligned borehole, the
first anchor attaining a final position substantially perpendicular to the
aligned borehole such that the first anchor penetrates the wall of the
aligned borehole to secure the first anchor in the aligned borehole; and
the second anchor being rotatable in two axes in the first borehole, one
axis being perpendicular to the first borehole and the other axis being in
alignment with the first borehole, the second anchor attaining a final
position substantially perpendicular to the first borehole such that the
second anchor penetrates the wall of the first borehole to secure the
second anchor in the first borehole, thereby securing the ligament or
ligament replacement between the first and second bone members.
9. A method for repairing a ligament or installing a ligament replacement,
the method comprising the steps of:
providing a first anchor attached to a first end of one of the ligament and
ligament replacement;
providing a second anchor attached to a second end of one of the ligament
and ligament replacement;
the first and second anchors being attached to the respective first and
second ends by suture;
inserting the first and second anchors with the ligament or ligament
replacement with an insertion tool through a first borehole disposed in a
first bone member into an aligned borehole in a second bone member such
that the first anchor is disposed in the aligned borehole and the second
anchor is disposed in the first borehole, rotating the first anchor with
the insertion tool about two axes in the aligned borehole, one axis being
perpendicular to the aligned borehole and the other axis being aligned
with the aligned borehole and obtaining a final position of the first
anchor substantially perpendicular to the aligned borehole such that the
first anchor penetrates the wall of the aligned borehole to secure the
first anchor in the aligned borehole;
rotating the second anchor with the insertion tool about two axes in the
first borehole, one axis being perpendicular to the first borehole and the
other axis being in alignment with the first borehole, and obtaining a
final position of the second anchor substantially perpendicular to the
first borehole such that the second anchor penetrates the wall of the
first borehole to secure the second anchor in the first borehole, thereby
securing the ligament or ligament replacement between the first and second
bone members; and
removing the insertion tool.
10. The method of claim 9, further comprising extending the aligned
borehole through the second bone member and threading a suture tied to the
first anchor through the extended aligned borehole, and further comprising
tieing off said suture to tension said first anchor.
11. The method of claim 10, further comprising tieing off a suture tied to
the second anchor to tension the second anchor.
12. The method of claim 9, further comprising providing tension on the
ligament or ligament replacement when rotating the second anchor.
Description
BACKGROUND OF THE INVENTION
The present invention relates to fixation devices or anchors and tools and
methods for emplacing same. The present invention, in particular, relates
to medical anchors, e.g., suture anchors or prosthesis anchors. It further
relates to a method and apparatus for emplacing an anchor in biological
material, for example, bone. Even more particularly, the present invention
relates to a medical anchor which can be inserted through a longitudinally
extending borehole so that the anchor is initially substantially aligned
with the borehole and then, via an emplacement tool, manipulated so that
the anchor pivots in two axes to form an undercut in the borehole and is
secured substantially perpendicularly to the longitudinal extent of the
borehole. The present invention is particularly suitable for the
emplacement of anchors adapted to repair ligaments, e.g., rotator cuff
ligaments, anterior cruciate ligaments (ACL's) and other ligaments. The
anchor is also suitable for prosthesis fixation.
In Applicant's co-pending U.S. patent application Ser. No. 08/470,988,
filed Jun. 6, 1995, a medical anchor is disclosed which can be emplaced in
a groove which extends substantially parallel to the surface of the bone.
The anchor of that patent application is placed in the groove, and then
rotated along an axis defined by the tool (and which axis is perpendicular
to the extent of the groove) to form an undercut in the walls of the
groove in the bone to secure the anchor. The anchor of that application is
suitable for repairing rotator cuff injuries, for example.
Applicant is also aware of U.S. Pat. No. 5,203,787 to Noblitt et al., in
which a suture anchor can be emplaced in bone. This anchor is inserted in
a longitudinally extending hole and then is twisted into place by
manipulation of the sutures so that the suture anchor pivots along an axis
which is perpendicular to the longitudinal axis of the borehole.
U.S. Pat. No 5,569,302 to Johnson describes an apparatus and method for
attaching an object to bone in which a special tool is provided to form a
groove which extends both longitudinally parallel to the bone and distally
into the bone and a special tool is utilized to form an undercut into
which the anchor is fitted.
The various prior art devices suffer from a number of defects. In the
above-described co-pending patent application, although a securely
emplaced anchor is obtained by using the device of that patent
application, it is necessary to form a groove which extends essentially
parallel to the surface of the bone. This is a more time consuming task
than simply drilling a borehole. The Noblitt et al. device requires the
manipulation of the sutures to emplace it, which may result in an
unreliable emplacement, and furthermore, requires a complex manipulation.
The Johnson reference requires a first tool for the formation of a
specialized groove which extends both essentially parallel to the surface
of the bone and distally into the bone and a another tool to form the
undercut for the anchor. Accordingly, the Johnson device and method is
unnecessarily complex.
There is a need in the medical art for an anchor which can be emplaced
simply and which is securely fastened into the bone.
There is a need also for a tool for installing such an anchor with simple
motions, and preferably one simple motion.
There is a need particularly for such an anchor which can be inserted into
a simple longitudinally extending borehole, i.e., a drilled borehole, and
which does not require complex, time consuming-to-make grooves or other
specialized manipulations.
There is a need for an anchor which can be inserted into a borehole
substantially in alignment with the borehole and once inserted, activated
so that it engages with the walls of the borehole by moving to a position
substantially perpendicular to the borehole.
Such an anchor would be suitable, for example, to repair rotator cuff and
other ligament injuries such that the appropriate attachment strength is
provided.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide an anchor which can be
easily emplaced and which provides sufficient strength for the attachment
of prosthesis or sutures for the reattachment of, for example, ligaments,
e.g., the rotator cuff or ACL ligaments.
Yet still a further object of the present invention is to provide an anchor
which can be inserted in a distally extending borehole and which is
adapted to be rotated in two axes so as to form an undercut in the
borehole into which the anchor is secured.
Yet still a further object of the present invention is to provide such an
which can be inserted longitudinally into a borehole and which can be
emplaced so that the anchor rotates into an undercut which the anchor
itself cuts into the borehole, the anchor rotating about one axis
extending perpendicular to the borehole and another axis extending along
the longitudinal axis of the borehole.
Yet still a further object of the present invention is to provide a tool
for emplacing the described anchor and for performing the manipulations to
form the undercut and secure the anchor in the borehole.
The above and other objects are achieved by a method for emplacing a
medical anchor in a borehole in biological tissue, the method comprising
the steps of providing a borehole in the biological tissue, inserting the
anchor into the borehole with a tool such that the anchor is affixed to
the tool and in approximate alignment with the borehole, manipulating the
tool, the step of manipulating the tool causing the anchor to pivot about
an axis perpendicular to the borehole and further comprising rotating the
anchor in the borehole about the axis of the borehole, thereby causing the
anchor to move outwardly in the borehole to engage a wall of the borehole
and cut into the wall of the borehole and secure the anchor in a final
position in the borehole such that the anchor is disposed approximately
perpendicularly to the axis of the borehole; and removing the tool from
the borehole by moving the tool proximally in the borehole, thereby
separating the anchor from the tool and leaving the anchor secured in the
borehole.
The above and other objects are also achieved by a medical anchor for
emplacement in a borehole in a biological tissue member, the anchor
comprising a central portion, at least one outer portion attached to the
central portion, the outer portion having a cutting edge, the anchor being
adapted to be inserted in the borehole in approximate alignment with a
longitudinal axis of the borehole, and further being adapted to be rotated
in two axes to secure the anchor in the borehole, a first axis of rotation
being aligned with the axis of the borehole and a second axis of rotation
being perpendicular to the axis of the borehole, whereby the anchor moves
outwardly about the second axis so that the cutting edge cuts into a wall
of the borehole and the anchor is rotated about the first axis to achieve
a final position substantially perpendicular to the borehole.
The above and other objects are furthermore achieved by an apparatus for
emplacing a medical anchor in a borehole in biological tissue the anchor
comprising a member having at least one portion adapted to cut into a wall
of the borehole to secure the anchor in the borehole, the apparatus
comprising a handle having a gripping surface, a shaft having a first
longitudinal axis, the shaft being attached to the handle and having a
distal end for insertion in the borehole, the distal end having a pivoting
receptacle for receiving the anchor initially in a position approximately
aligned with the first axis, a pushing member movable distally with
respect to the shaft to push on the anchor in the pivoting receptacle, the
shaft being rotatable about the first axis, the pushing member being
movable distally with respect to the shaft to rotate the anchor in the
pivoting receptacle about a second axis substantially perpendicular to the
shaft, thereby causing the at least one portion of the anchor to move
outwardly and cut into the wall of the borehole to secure the anchor in
the borehole, the anchor rotating about said first and second axes to
secure the anchor in the borehole with the anchor being secured in a final
position approximately perpendicular to the first axis.
The above and other objects of the present invention are also achieved by
an apparatus for emplacing a medical anchor in a borehole in biological
tissue, the anchor comprising a member having two opposed portions adapted
to cut into walls of the borehole to secure the anchor in the borehole,
the apparatus comprising a handle having a gripping surface, a shaft
having a first longitudinal axis, the shaft being attached to the handle
and having a distal end for insertion in the borehole, the distal end
having a pivoting receptacle for receiving the anchor initially in a
position approximately aligned with the first axis, a pushing member
disposed in a channel in the shaft, the pushing member being slidably
movable distally in the shaft to push on the anchor in the pivoting
receptacle, a slidable collar disposed slidably on the shaft and attached
to the pushing member, the slidable collar being movable distally on the
shaft as the shaft is rotated about the first axis to cause the pushing
member to move distally to rotate the anchor in the pivoting receptacle
about a second axis substantially perpendicular to the shaft, thereby
causing the two opposed portions of the anchor to move outwardly and cut
into the walls of the borehole to secure the anchor in the borehole, the
anchor rotating simultaneously about said first and second axes to secure
the anchor in the borehole with the anchor being secured in a final
position approximately perpendicular to the first axis.
The above and other objects are furthermore achieved by an anchor for
emplacement in a borehole in a biological tissue, the anchor comprising, a
cutting member having, a central portion having a securement point for a
prosthesis; and at least one outer portion attached to the central
portion, the outer portion having a cutting edge, a pivoting receptacle
for the cutting member comprising a carrier member, the carrier member
being receiving in a support washer, the support washer having a region
for engaging a surface of the tissue surrounding the borehole, the anchor
being adapted to be inserted in the borehole with the cutting member in
approximate alignment with a longitudinal axis of the borehole, and
further wherein the cutting member is adapted to be rotated in two axes to
secure the anchor in the borehole, a first axis of rotation being aligned
with the axis of the borehole and a second axis of rotation being
perpendicular to the axis of the borehole, whereby the cutting member
moves outwardly about the second axis so that the cutting edge cuts into a
wall of the borehole and the anchor is rotated about the first axis to
achieve a final position substantially perpendicular to the borehole.
The above and other objects are also achieved by an apparatus for repairing
a ligament or installing a ligament replacement, the apparatus comprising,
a first anchor attached to a first end of the ligament or ligament
replacement, a second anchor attached to a second end of the ligament or
ligament replacement, the first and second anchors being attached to the
respective first and second ends by suture, the first and second anchors
with the ligament or ligament replacement being insertable through a first
borehole disposed in a first bone member into an aligned borehole in a
second bone member such that the first anchor is disposed in the aligned
borehole and the second anchor is disposed in the first borehole, the
first anchor being rotatable about two axes in the aligned borehole, one
axis being perpendicular to the aligned borehole and the other axis being
aligned with the aligned borehole, the first anchor attaining a final
position substantially perpendicular to the aligned borehole such that the
first anchor penetrates the wall of the aligned borehole to secure the
first anchor in the aligned borehole and the second anchor being rotatable
in two axes in the first borehole, one axis being perpendicular to the
first borehole and the other axis being in alignment with the first
borehole, the second anchor attaining a final position substantially
perpendicular to the first borehole such that the second anchor penetrates
the wall of the first borehole to secure the second anchor in the first
borehole, thereby securing the ligament or ligament replacement between
the first and second bone members.
The above and other objects are also achieved by a method for repairing a
ligament or installing a ligament replacement, the method comprising the
steps of, providing a first anchor attached to a first end of the ligament
or ligament replacement, providing a second anchor attached to a second
end of the ligament or ligament replacement, the first and second anchors
being attached to the respective first and second ends by suture,
inserting the first and second anchors with the ligament or ligament
replacement with an insertion tool through a first borehole disposed in a
first bone member into an aligned borehole in a second bone member such
that the first anchor is disposed in the aligned borehole and the second
anchor is disposed in the first borehole, rotating the first anchor with
the insertion tool about two axes in the aligned borehole, one axis being
perpendicular to the aligned borehole and the other axis being aligned
with the aligned borehole and obtaining a final position of the first
anchor substantially perpendicular to the aligned borehole such that the
first anchor penetrates the wall of the aligned borehole to secure the
first anchor in the aligned borehole, rotating the second anchor with the
insertion tool about two axes in the first borehole, one axis being
perpendicular to the first borehole and the other axis being in alignment
with the first borehole, and obtaining a final position of the second
anchor substantially perpendicular to the first borehole such that the
second anchor penetrates the wall of the first borehole to secure the
second anchor in the first borehole, thereby securing the ligament or
ligament replacement between the first and second bone members and
removing the insertion tool.
The above and other objects are also achieved by an apparatus for repairing
a ligament or installing a ligament replacement, the apparatus comprising:
an anchor attached to a first end of the ligament or ligament replacement,
the anchor being attached to the first end by suture, the anchor with the
ligament or ligament replacement attached thereto being insertable into a
borehole disposed in a bone member such that the anchor is disposed in the
borehole initially substantially in alignment with the borehole, the
anchor being rotatable about two axes in the borehole, one axis being
perpendicular to the borehole and the other axis being aligned with the
borehole, the anchor attaining a final position substantially
perpendicular to the borehole such that the anchor penetrates the wall of
the borehole to secure the anchor with the ligament or ligament
replacement attached thereto in the borehole.
The above and other objects are further achieved by a method for repairing
a ligament or installing a ligament replacement, the method comprising the
steps of: providing an anchor attached to a first end of the ligament or
ligament replacement, the anchor being attached to the first end by
suture, inserting the anchor with the ligament or ligament replacement
attached thereto with an insertion tool into the borehole in a bone member
such that the anchor is disposed initially substantially in alignment with
the borehole, rotating the anchor with the insertion tool about two axes
in the borehole, one axis being perpendicular to the borehole and the
other axis being aligned with the borehole and obtaining a final position
of the anchor substantially perpendicular to the borehole such that the
anchor penetrates the wall of the borehole to secure the anchor with the
ligament or ligament replacement attached thereto in the borehole.
Other objects, features and advantages of the present invention will be
apparent from the detailed description which follows.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a partially cutaway plan view of an emplacement tool according to
the present invention for emplacing the anchor according to the present
invention.
FIG. 1A is a perspective detail of FIG. 1;
FIG. 2 is a plan detail of FIG. 1;
FIG. 3 is a plan detail of FIG. 1;
FIG. 4 is a perspective exploded view of the anchor emplacement tool
according to the present invention;
FIGS. 5A-5F show one manner of forming some of the components of the anchor
emplacement tool according to the present invention;
FIG. 6 shows a perspective detail of the emplacement tool;
FIG. 6A is a perspective partial view showing a detail of the emplacement
tool according to the present invention;
FIG. 6B is an end view of FIG. 6;
FIG. 7 is an alternative embodiment of a portion of the emplacement tool;
FIGS. 8A-8J show, in perspective views, details of the distal portion of
the tool as it is emplacing an anchor in a borehole, with the borehole not
shown;
FIG. 9 is an exploded perspective view of the distal end of the emplacement
tool and the anchor;
FIG. 10 is a perspective view of the anchor according to the present
invention with sutures attached thereto;
FIG. 11 is a perspective detailed view of a modified form of the anchor
according to the present invention;
FIGS. 12A & 12B show the beginning and ending steps employed in emplacing
the anchor according to the present invention;
FIG. 13 shows a prosthesis anchor according to the present invention and a
tool for emplacing the anchor;
FIGS. 13A, 13B and 13C show steps in the emplacement of the anchor of FIG.
13 using the tool of FIG. 13;
FIG. 14 shows an alternative anchor emplacement tool for an anchor of the
type shown in FIGS. 10 or 11;
FIG. 15 shows anchors according to the present invention being used for
repair of a ligament, and in particular, the ACL;
FIG. 16 shows the anchor of FIG. 15 in a perspective view after
emplacement; and
FIG. 17a-f show the steps of emplacing anchors according to the present
invention to repair an ACL.
DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION
With reference now to the drawings, FIG. 1 is a partially cutaway plan view
of a tool for emplacing an anchor, e.g., a medical anchor such as a suture
anchor or prosthesis anchor. The tool is generally indicated at 10. The
anchor emplaced by the tool is shown at 20 and in this embodiment,
comprises a suture anchor. The tool comprises a handle 12, a
longitudinally extending central hollow shaft 14 which is secured to the
handle 12, a collar 16 which is provided fixed on the shaft 14 and turns
with the shaft 14 and is disposed adjacent to handle 12, and an exteriorly
threaded sliding collar 18 which is slidable upon the collar 16 of shaft
14. Collar 18 has a threaded portion 20. Collar 18 is adapted to slide on
the collar 16 of shaft 14.
The threads 20 of collar 18 are threadably received in an external gripping
member 22 which is provided with handgrips to be grasped by a surgeon's
hand. Collar 18 has fixedly attached thereto for movement therewith a
pushing channel 24. See FIGS. 1A and 4. Pushing channel 24 is slidable
within a slot 26 provided in the collar 16. The pushing channel 24 further
extends throughout and is slidable in a channel 28 provided in the shaft
14. See FIG. 4. The shaft 14 terminates in a pivoting receptacle 30 at the
distal end. The shaft 14 at the distal end has cutouts 32 serving as a
seat for the anchor 20 during initial insertion so that the anchor is
initially approximately aligned with the longitudinal axis of shaft 14.
The anchor 20 is approximately disposed along the longitudinal axis of
shaft 18 during initial insertion, although at a slight angle with respect
to the axis of shaft 14. See FIG. 1 and FIG. 9. The anchor 20 according to
the invention, which will be described in greater detail below, is thus
received in the pivoting receptacle 30 during initial insertion into a
borehole such that it is approximately aligned with the borehole,
facilitating insertion. The anchor 20 preferably includes two opposed
blade portions 20A and 20B which are adapted to cut into bone when the
anchor 20 is rotated in two axes, to be explained in greater detail below.
The pushing channel 24 is adapted to push against a cam surface of the
anchor 20 to allow it to rotate in the axis of the receptacle indicated by
line B--B of FIG. 4. At the same time, rotation of the handle 12 rotates
the anchor 20 about the axis of the borehole, securing the anchor in the
borehole. This will be described in further detail below. Although the
anchor shown is a suture anchor, it may be a prosthesis anchor and
emplaced to secure a prosthesis in, e.g., bone. Additionally the anchor 20
shown has two portions 20A and 20B. However, an anchor according to the
invention can be provided having only one portion 20A having a single
cutting edge for cutting into the wall of a borehole to secure the anchor.
The pushing channel 24 is preferably provided as a channel so that if the
anchor 20 comprises a suture anchor, the sutures 40 which are threaded
through the suture anchor 20 can extend through the channel 24 in shaft 14
and through a longitudinally extending channel 34 provided in the handle
12. The sutures are then conveniently tensioned by twisting them around a
holding member, e.g., a flexible plastic or rubber grommet 36 which is
secured on the handle 12 by a screw 38. The sutures are indicated by the
lines 40. Pushing channel 24 may reduce in thickness as shown at 25.
Gripping member 22 is internally threaded with threads 42 which threadingly
engage with threads 20 of the slidable collar 18 and is provided with a
suitable gripping surface 44. The gripping member 22 is provided so that
the shaft 14 can rotate therein. Gripping member 22 is coupled to a
further shaft 46 which is disposed concentrically about shaft 14. Shaft 46
terminates with a "V" shaped end 48. The purpose of "V" shaped end 48 is
to provide a surface which will engage with the bone surface surrounding a
borehole to maintain the tool in position during emplacement of the anchor
and to maintain the anchor at the desired emplacement depth in the
borehole. This will be explained in greater detail below. See also FIGS.
12A and 12B.
As shown by comparing FIGS. 1 and 3, and reviewing FIGS. 8A-8J, the anchor
20 is emplaced as follows. The surgeon inserts the tool, with the anchor
20 received in the pivoting receptacle 30 at the distal end thereof and
generally aligned with the axis of the tool, into a predrilled borehole in
the bone. The anchor 20 at this time is approximately directed along the
axis of the shaft 14. See FIG. 8A, which corresponds to FIG. 1. The
sutures 40, as explained previously, are looped through apertures in the
suture anchor 20 and extend through the pushing channel 24 which is
disposed in the interior of hollow shaft 14. See FIG. 10. The sutures then
extend through the handle 12 and are suitably tensioned by grommet 36,
holding the suture anchor 20 securely in pivoting receptacle 30.
Once the tool with the anchor 20 has been placed at the desired depth in
the borehole in the bone, as determined by the distal location of end 48
of shaft 46, the surgeon holds the gripping member 22 stationary in one
hand and turns the handle 12, also provided with a gripping surface, with
the other hand. Alternatively, other embodiments of the tool can be
developed whereby the tool can be operated with one hand. This
manipulation causes the shaft 14 to rotate, imparting this rotation to
pusher channel 24 disposed in channels 26 and 28, which in turn imparts
the rotation to collar 18. The threads 20 on collar 18 thus move with
respect to the threads 42 of the stationary gripping member 22. The entire
threaded collar 18 thus slides on the collar 16 of shaft 14. The movement
of the collar 18 in the gripping member 22 will cause the pushing channel
24, which is affixed to the collar 18, to move toward the distal end. The
distal end 24A of the pushing channel 24 is in engagement with a cam
surface of the anchor 20. As the collar 18 moves distally with respect to
the gripping member 22, and thus with respect to the shaft 14, the pushing
channel 24 also moves distally, causing the anchor 20 to pivot about line
B--B in the receiving receptacle 30. At the same time, since the shaft 14
is rotating, the anchor 20 cuts into the bone as it moves radially
outwardly. The anchor rotates in two axes: one axis along line B--B as it
is forced outwardly by pushing channel 24 and a second axis aligned with
the axis of shaft 13 as shaft 14 is rotated. The anchor thus moves in a
spiral path as it expands radially outwardly and cuts into the bone due to
the combined action of shaft 14 turning and pusher channel 24 moving
distally.
The anchor 20 has cutting surfaces 20AA and 20BB disposed on opposite
portions of the respective anchor portions 20A and 20B. See FIG. 10. As
the shaft 14 rotates and the pushing channel 24 moves distally, the anchor
20 executes a spiral motion as the portions 20A and 20B begin to move
radially outwardly cutting into the wall of the borehole in the bone. The
shaft 14 may turn through approximately 90 to 180.degree., depending upon
the amount the handle 12 is turned and the distance D (FIG. 1) through
which the threaded collar 18 can move with respect to the gripping member
22. Compare FIGS. 1 and 3.
FIG. 4 shows an embodiment of the anchor emplacement tool according to the
invention wherein a nut 50 has been embedded in the gripping member 22 to
provide the internal threads 42 with which threads 20 of the threaded
collar 18 engage. FIG. 1 shows the member 22 with internally formed
threads 42 formed integrally with the member 22. Alternatively, an
internally threaded insert can be provided in the member 22 to form the
threads 42. In FIG. 4, the nut 50 is pinned into position in the gripping
member 22 as shown by pins 51.
FIGS. 5A-5B show one method of making the threaded collar 18. Threaded
collar 18 may be made from a bolt 18A. The head 18B of the bolt 18A is cut
off as shown in FIG. 5B. A bore 18C is formed concentrically in the
threaded bolt 18A. A key 18D is formed having a curved surface 18E. The
key 18D has the pushing channel 24 welded thereto. The surface 18E of the
key 18 is thereafter welded and/or pinned, as shown at 18F and 18G, to the
drilled, threaded bolt 18A. The threaded collar 18 thus turns with the
pushing channel 24 as the pushing channel 24 turns with rotating shaft 14.
As shaft 14 turns, the collar 18 moves in the threads of gripping member
22. As explained, the pushing channel 24 thus moves distally as it rotates
in the rotating shaft 14, causing the anchor 20 to pivot in the pivoting
receptacle 30 about axis B--B, thus extending radially outwardly as the
shaft 14 turns. The anchor 20 spirals radially outwardly as the cutting
edges of the anchor undercut into the walls of the borehole. The anchor
thus undergoes two pivoting motions: about line B--B of receptacle 30 and
along the axis of shaft 14.
FIG. 7 shows an alternative embodiment of the collar 16. In the embodiment
of FIG. 6, the collar 16 has vertically cut surfaces 16A and 16B which
assist in imparting the rotation of the shaft 14 to the threaded collar 18
through key 18D. In the embodiment of FIG. 7, only the vertical walls of
the channel 28 impart the rotation of the shaft 14 to the pushing channel
24 which in turn imparts rotation to the threaded collar 18. Accordingly,
the embodiment of FIG. 6 is somewhat stronger than the embodiment shown in
FIG. 7.
FIGS. 8A-8j show the steps employed in emplacing the anchor 20. The shaft
14 with the anchor 20 mounted in the pivoting receptacle 30 is inserted in
the borehole into the bone, not shown. The handle 12 is turned while the
gripping member 22 remains stationary. This turning motion causes the
shaft 14 to rotate as shown in FIGS. 8A-8j. While the shaft 14 is
rotating, the rotation of the shaft is imparted to the pushing channel 24
and key 18D which is in turn imparted to the threaded collar 18. The
threaded collar 18 is threaded in the gripping member 22 and accordingly,
it slides on the collar portion 16 which is affixed to shaft 14. This
causes the threaded collar 18 to slide on the shaft 14, causing the
pushing channel 24 to move distally. The distal end 24A of the pushing
channel 24 cams against the anchor 20 cam surface 20B' (FIGS. 9 and 10),
causing it to spiral out radially as the shaft 14 is turned.
The cutting edges 20AA and 20BB of anchor 20 cut into the walls of the
borehole to secure the anchor into the borehole. Once secured, the sutures
40 are released from tensioning grommet 30 and the tool 10 is moved in the
proximal direction as shown by the arrow P in FIG. 8J, causing the secured
anchor 20 to detach from the pivoting receptacle 30 in which it is held.
The tool 10 is pulled out of the borehole and clear of the sutures 40,
leaving the anchor 20 with the sutures attached to the anchor in the bone.
A detached ligament or a prosthesis can then be secured to the sutures 40.
As also shown in FIG. 8A, a spring 60 may be provided to impart downward
pressure on the pusher channel 24, in accordance with the embodiment of
the tool shown in FIG. 14 to be described below.
FIG. 10 shows details of a suture anchor 20. As shown, the suture anchor
includes two opposed portions 20A and 20B. Portion 20A has cutting edge
20AA and portion 20B has cutting edge 20BB disposed on opposite sides of
the anchor. Between the portions 20A and 20B, a central portion 20C is
disposed having two openings 20CC through which the suture 40 is looped.
To assist in looping the sutures through the openings 20CC, a sloping
surface 20CCC may be provided as shown. Similarly, a surface to assist the
suture through the other opening 20CC may be provided on the bottom side
of the anchor 20, not shown.
FIG. 11 shows an alternative embodiment of the anchor 20. Unlike the
embodiment of FIG. 10, which has angled sidewalls 21, this anchor has
substantially vertical sidewalls 21A as shown and a flat upper surface of
the central portion 20C, as indicated at 23A, in contrast to the curved
surface 23 of the anchor of FIG. 10.
FIGS. 12A and 12B show the beginning and ending steps of emplacing the
anchor. FIG. 12 shows the beginning step where the shaft 14 is emplaced in
the bore hole 70 in bone. FIG. 12A corresponds to FIG. 8A. FIG. 12B
corresponds to FIG. 8I. Once the anchor 20 has been emplaced in the
self-made undercut, as shown in FIG. 12B, the shaft 14 is withdrawn, as
shown in FIG. 8J. The spiral movement of the anchor 20 as it is emplaced
is shown by dashed curved line 72.
Although the anchor of the present invention is adapted to cut into both
the harder cortical bone layer and the softer sub-cortical cancellous
region, one preferred method of emplacing the anchor comprises emplacing
the anchor so that it has a final position, as shown in FIG. 12B, wherein
the anchor is disposed perpendicular to the borehole just below the
cortical layer. The transition from cortical to sub-cortical regions is
shown by dashed line 80 in FIG. 12B. By pulling the tool, and thus the
anchor, in the proximal direction, the surgeon can be assured that the
anchor is secured just below the cortical region.
FIG. 13 shows a prosthesis anchor 91 which has an anchor member 20' which
is substantially the same as the suture anchor 20 of FIGS. 10 and 11
except that in the central portion 20C', the prosthesis anchor member 20'
has a threaded opening 90 instead of openings for looping a suture
therethrough. In addition, the prosthesis anchor member 20' includes two
pivot projections 92, which are received in openings 94 of a carrier 96.
The carrier 96 is provided with ratcheting or gripping serrations 98 on
its exterior surface which are adapted to be received in mating serrated
interior surface 100 of a shouldered washer 102. The carrier 96 is
additionally provided with torque transmission openings 104 which are
adapted to receive torque transmission projections 106 on a cylindrical
member 108 of an inserter tool 112. The inserter tool 112 includes a
pusher member 110 which is similar to the pushing channel 24 of the tool
of FIG. 1 and serves the same function of camming against the anchor
member 20' to rotate the anchor member about axis B'--B' of FIG. 13.
As shown in FIGS. 13A-13C, the anchor 91 of FIG. 13 is emplaced as follows:
The carrier 96 with anchor member 20' attached in the pivoting openings 94
of carrier 96 is secured in the washer 102. The serrations 98 and 100
allow the carrier 96 to be snapped into the washer 102 so that the carrier
96 detents into a desired position in the washer 102. The inserter tool
112 is thereafter secured in the washer 102 such that the projections 106
are received in the openings 104 of the carrier 96. The projections 106
are radially movable by a mechanism not shown so that they can be inserted
into the washer 102 and move into position, for example, by snapping into
position against spring pressure into the openings 104 in the carrier 96.
As discussed, the projections 106 are provided as torque transmission
means so that when the tool 112 is rotated, the carrier 96 with the anchor
member 20' affixed thereto rotates along the axis of the tool 112. Tool
112 may otherwise be the same as the tool 10 shown in FIG. 1, having only
a different distal end, as shown in FIG. 13. Otherwise, the tool operates
in the same way to move the pusher member 110 distally while the tool is
rotated.
As shown in FIG. 13A, the tool, generally shown at 112 with the end 108
having the carrier 96, washer 102 and anchor member 20' attached thereto,
is inserted into the borehole 70 in the bone 72. As shown, the anchor
member 20' is substantially aligned initially with the axis of the tool.
Thereafter, the tool 112 is rotated. This rotation, as in the embodiment
of FIG. 1, causes the pusher member 110 to move distally, thus causing the
anchor member 20' to rotate about the axis B'--B' at the same time that it
rotates about the axis of the tool 112. This causes the anchor member 20'
to move outwardly and cut into the wall of the borehole, eventually
obtaining the final position shown in FIG. 13B. As shown in FIG. 13B, the
anchor member has been emplaced directly below the cortical layer of the
bone. The transition between cortical and subcortical bone is shown by
line 80. In order to ensure that the anchor member is secured below the
cortical layer, a force F in the proximal direction, as shown by the
arrows F, may be applied to the anchor by pulling up on the tool 112 as
shown by arrow 113. At the same time, a shoulder 109 of the tool 112 bears
down on the washer 102 to prevent the washer 102 from pulling out of the
borehole. The carrier 96 may move upwardly in the serrations 100 of the
washer 102 and detent into position in the washer 102 to apply tension to
the anchor member 20'. The tool is then actuated to release the
projections 106 from the openings 104, thereby releasing the tool 112 from
the anchor 91.
Thereafter, a screw 114 may be threaded into the threaded aperture 90 in
the anchor member 20' to secure a prosthesis or any other device, such as
the bone plate 115 shown, to the bone 72.
Turning now to FIG. 14, an alternative embodiment of a tool for emplacing
an anchor according to the present invention is shown. The tool as shown
in FIG. 14 is also shown as emplacing a suture anchor 20. The tool
includes a handle 12' having a suture tensioner such as a grommet and
screw 36', 38' about which the sutures 40 are tensioned. As in the
embodiment in FIG. 1, a pushing member 24' is provided comprising a
pushing channel through which the sutures 40 are threaded. The pushing
channel 24' is provided in a shaft 14' having a channel to receive the
pushing channel 24'. The shaft 14' is provided with a receiving receptacle
30' as in the embodiment described with respect to FIG. 1. A collar 46' is
provided near the distal end of the shaft 14' and affixed to the shaft
14'. The purpose of the collar 46' is to locate the tool adjacent the bone
at the perimeters of the borehole and to position the suture anchor 20 at
the desired depth in the borehole in the bone.
In the handle 12' a spring 60 is provided to exert a biasing force on the
pushing channel 24'. A pin 43 is disposed through an aperture in the
pushing channel 24' initially to maintain the pushing channel in its
proximal position. A button 45 is provided which can be actuated by the
surgeon to allow the pushing channel 24' to move distally against the
urging of the spring 60.
Accordingly, in use, the surgeon positions the tool in alignment with the
borehole and then inserts the anchor affixed in the receiving receptacle
30' into the borehole. The surgeon then actuates the button 45 which
removes the pin 43 from the opening in the pushing channel 24'. The action
of the spring 60 urges the pushing channel 24' against the anchor 20,
causing it to rotate about the axis B"--B". This urges the anchor 20
outwardly so that it engages with the wall of the borehole in the bone. At
the same time, the handle 12' is rotated, causing the anchor 20 to cut
into the wall of the borehole. The anchor will execute a spiral motion
because of the two pivoting actions. The shoulder 46' will keep the
pivoting receptacle 30' in a fixed location as the anchor 20 executes a
spiral motion to cut into the bone to secure the anchor in the bone.
Once the anchor 20 has been secured in a position approximately
perpendicular to the axis of the borehole, the tension in the sutures 40
may be removed by removing the sutures 40 from the suture tensioner
36'--38', and pulling proximally on the tool 10', thereby releasing the
anchor from the pivoting receptacle 30'. The sutures can now be affixed to
other tissue, for example, a ligament, or to a prosthesis.
FIGS. 15, 16 and 17a-f show how the anchor according to the present
invention may be used to repair a ligament or to attach a prosthetic
ligament, for example, for ACL repair.
FIG. 15 shows schematically the femur F and tibia T of a human knee joint.
An anchor 20F coupled to a ligament or ligament replacement L is
positioned in the femur, initially aligned with a borehole made in the
tibia and the femur. Anchor 20F is coupled to ligament L. The other end of
ligament L is sutured to another anchor 20 T, which is positioned on the
tibia.
As shown in FIG. 15 and as also shown in FIGS. 17a-f, the borehole in the
tibia T is made of a sufficient diameter to allow a cannulated anchor
setting tool to be inserted into the borehole with the two anchors, the
ligament L and the sutures contained in alignment in the canula of the
insertion tool. The femur F is made with a borehole which is of a first
diameter to allow the tool and the anchor 20F to be inserted therein, and
which is bored through with a smaller diameter as indicated at 150, which
allows the sutures 40 to be passed therethrough. FIG. 16 shows the anchors
20F and 20T after they have been rotated by 90.degree. (along two axes, as
in the other embodiments described) and have cut into the boreholes in the
femur and tibia respectively. The femur and tibia are not shown in FIG.
16.
With reference to FIGS. 17a-f, the anchors 20T and 20F of the invention are
installed for ACL repair as follows: First, a borehole is made through the
tibia as shown in FIGS. 17a-f. Second, a borehole 150 of a smaller
diameter aligned with the borehole in the tibia is made in the femur as
shown. The smaller borehole 150 is then counter-drilled to have a diameter
the size of the borehole in the tibia but does not extend the entire
distance of the borehole in the tibia. The ligament or ligament
replacement L is sutured by sutures 40 to anchor 20F and 20T. The anchors,
sutures and ligament L are then placed in the canula of a cannulated tool,
shown in FIG. 17c at ct. The tool is then inserted through the tibia
opening and into the femur, at which point, as shown in FIG. 17b, the
anchor 20F is manipulated to rotate along two axes into a position
90.degree. to the axis of the borehole. The sutures 40 have been
previously inserted completely through the borehole 150 and now extend out
of the distal end of the femur borehole 150. As shown in FIG. 17c, the
sutures 40 are tensioned and a suitable knot 152 is made in the sutures to
tie the sutures off in the femur and to tension the anchor 20F.
As shown in FIG. 17d, the tool is now actuated to manipulate the anchor 20T
in the tibia to pivot the anchor along two axes in the tibia approximately
90.degree. to the axis of the borehole. At the same time, suitable tension
is applied by the tool to properly tension member L.
The tool is then withdrawn, as shown in FIG. 17e. A force X is exerted on
the sutures 40 to tension the anchor 20T in the tibia. The sutures are
then tied off and cut as shown in FIG. 17f. When the suture 20T in the
tibia is set, a suitable tension is applied by the tool to obtain the
desired tension in the ligament or ligament replacement L.
Although repair of the ACL is shown, the invention may also be used for
repair of other ligaments in other skeletal joints.
Although the present invention has been described in relation to particular
embodiments thereof, many other variations and modifications and other
uses will become apparent to those skilled in the art. Therefore, the
present invention should be limited not by the specific disclosure herein,
but only by the appended claims.
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